Elevator control device

ABSTRACT

A speed control device for an elevator includes a flat disc having a spiral groove radiating from the center embedded in one face. A control arm pivoted for rotational movement about the axis of the disc generates a speed reference signal as a function of the displacement of the arm from a neutral position. An accelerating motor displaces the control arm in a direction opposite to the direction in which the disc is being rotated in synchronism with the movement of the car. A carriage mounted for longitudinal movement along the control arm is coupled to the disc so that it tracks the groove in the disc. When the car is to be slowed down, pawls carried on the carriage are extended so that floor stops inserted in the spiral groove at points corresponding to the positions of the landings will engage the control arm and drive the control arm toward the neutral position thereby reducing the speed reference signal. A three-wire signal generator also mounted on the carriage cooperates with additional stops on the rotating disc to generate notching signals for a floor selector as the car passes predetermined points between the landings. The mass of the components associated with the control arm is concentrated near the center of rotation of the arm to reduce impact forces during pawling.

United States Patent Caputo Aug. 29, 1972 [s41 ELEVATOR CONTROL DEVICE [72] Inventor: William R. Caputo, Wyckoff, NJ.

[73] Assignee: W Electric Corporation,

Pittsburgh, Pa. [22] Filed: June 11, 1971 [21] Appl. No.: 152,079

5 2 Us. c1. ..1s7/29 R 511 1m. (:1. ..B66b 1/26 [58] Field of Search... ..187/29 [56} References Cited UNITED STATES PATENTS 3,554,325 1/1971 Savage ..1s7/29 3,507,361 4 1970 Savage ..1s7/29 Primary Examiner-Bernard A. Gilheany Assistant Examiner-W. E. Duncanson, Jr. Attorney-A. T. Stratton, Donald R. Lackey and Richard V. Westerhoff 1 FLOOR [57] ABSTRACT A speed control device for an elevator includes a flat disc having a spiral groove radiating from the center embedded in one face. A control arm pivoted for rotational movement about the axis of the disc generates a speed reference signal as a function of the displacement of the arm from a neutral position. An accelerating motor displaces the control arm in a direction opposite to the direction in which the disc is being rotated in synchronism with the movement of the car. A carriage mounted for longitudinal movement along the control arm is coupled to the disc so that it tracks the groove in the disc. When the car is to be slowed down, pawls carried on the carriage are extended so that floor stops inserted in the spiral groove at points corresponding to the positions of the landings will engage the control arm and drive the control arm toward the neutral position thereby reducing the speed reference signal. A three-wire signal generator also mounted on the carriage cooperates with additional stops on the rotating disc to generate notching signals for a floor selector as the car passes predetermined points between the landings. The mass of the components associated with the control arm is concentrated near the center of rotation of the arm to reduce impact forces during pawling.

14 Claims, 19 Drawing Figures SUPERVISORY CONTROL SYSTEM PATTERN GENERATOR AND SELECTOR PATENIEDM B 9 3.687.236 saw 010! I0 SPEED I SUPERVISORY CONTROL REGULATOR SYSTEM TRANSMITTER IS a PATTERN DM RECEIVER GENERATOR AND SELECTOR Io FLOOR l FULL WAVE RECTIFIER PATENTEDwszs I972 SHEET 030F 10 PATENTED I97? 3.687236 SHEET USUF 10 PATENTEmusze m2 SHEET U8 0F 10 NQNHJ PAIENIEDmszs M 3.697 236 sum as nr 10 FIG. I2

FIG. l4

ELEVATOR CONTROL DEVICE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to elevator control devices and more specifically to such devices which combine the function of controlling the speed of the elevator and tracking the position of the car.

2. Description of the Prior Art Many devices have been developed over the years for controlling the speed of elevator cars. Precise speed control which is essential for the safety and comfort of passengers, is complicated by the fact that the stopping point of the elevator car may be altered while the car is in motion.

Acceleration is usually controlled either as a stepwise or continuous function of time while deceleration is usually controlled as a function of the distance to go. In the prior art systems,-the distance to go has been established by a series of switches carried on the car or by various electromechanical models.

The commonly owned application of Conwell Savage, Ser. No. 817,789 filed on Apr. 21, 1969, now US. Pat. No. 3,554,325, discloses an elevator speed control wherein a helical frame is threadedly advanced in synchronism with the movement of the car. A control arm pivoted about the axis of the helix is rotationally displaced from a neutral position by the same shaft that drives the helical frame through a reversing gear and a clutch. A speed reference signal is generated as a function of the displacement of the control arm from the neutral position. When the car is to be stopped, pawls on the control arm are extended so that they engage floor stops distributed along the helical frame at points corresponding to the locations of the landings in the hoistway.

Although the Savage device is adequate to control slower speed cars, pawling forces become excessive when the device is adapted for higher speed elevators. These difficulties can be traced to the scale of the device and the concentration of mass at the end of the control head.

Many of the prior art mechanisms provide means for resynchronizing the device with the position of the car should it become necessary. This is especially true in systems wherein a separate device such as a landing inductor system is utilized to bring the car into exact registry with a landing. Examples of systems of this type can be found in US. Pat. Nos. 3,051,267 and 3,410,367.

The Sanford US. Pat. No. 1,913,043 discloses a floor selector which sequentially generates three control signals for operating an impulse motor which advances a mechanism for tracking the position of the elevator car. The device is not utilized to control the speed of the elevator car.

SUMMARY OF THE INVENTION According to this invention, a disc having a spiral groove embedded in one face is rotated about its axis in synchronism with the movement of an elevator car, preferably in a horizontal plane. A control arm pivoted about the axis of the disc is rotated in a plane parallel to the face of the disc by an accelerating motor. A pattern signal generator develops a speed reference signal as a function of the displacement of the control arm from a neutral position. The control arm is displaced by the accelerating motor in a direction opposite to the direction of rotation of the disc thereby generating an advanced car position relative to floor stops distributed along the spiral groove at points corresponding to the landings. I

A carriage mounted for longitudinal movement along the control arm is coupled to the rotating disc so that it tracks the spiral on the disc. When the car is to be slowed down, pawls carried on the carriage are extended so that they may be engaged by the floor stop corresponding to the landing at which it is desired that the car be brought to a stop. With the control arm coupled to the rotating disc, the speed of the car is reduced as the control arm returns to the neutral position.

The car may not be started unless the control arm is in the neutral position to prevent large rates of change of acceleration which would accompany the start with the pattern generator set for a high speed. To this end, means are provided for centering the control arm should it be displaced from the neutral position when the car has stopped as for an emergency stop.

In the embodiment of the invention disclosed, the disc is rotated in synchronism with the movement of the car by a selsyn drive. Despite the type of drive uti1- ized, it is possible that the turntable or disc could get out of synchronization with the car, hence apparatus for resynchronizing the table and the position of the car are provided.

The invention also encompasses the generation of signals representative of the position of the car with respect to the landings. To this end, a three-wire signal generator is also mounted on the carriage for tracking the spiral on the disc. Notching stops are mounted to the disc at points where they actuate the three-wire signal generator when the car is at a predetermined point, such as half-way, between floors. The three-wire signal generator operates a stepping motor which advances a wiper arm in a direction dependent upon the sequence in which the three signals are generated.

In order to avoid interference between the operation of the pawls and the three-wire signal generator, the pawls are mounted on one end of the carriage and track one-half of the spiral, while the three-wire signal generator is mounted on the other end and tracks the other half of the spiral. Preferably the pawls, which control the speed of the car during deceleration, track the outer half of the spiral where the scaling is maximum.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of an elevator system embodying the invention;

FIG. 2 is a plan view with some parts missing and some parts cut-away of a control device according to the invention;

FIG. 3 is an elevation view with some parts in sections and some parts broken away of the device shown in FIG. 2;

FIG. 4 is an enlarged view of a portion of FIG. 2 with some parts removed;

FIG. 5 is similar to FIG. 4 with the parts shown in a different operating position;

FIG. 6 is an elevation view with parts in section taken from the viewpoint indicated by the arrows VIVI in FIG. 2;

FIG. 7 is an enlarged side elevation view with some parts broken away of the control arm appearing in FIGS. 2 and 3;

FIG. 8 is a plan view with parts broken away of a portion of the control arm illustrated in FIG. 7;

FIG. 9 is a sectional elevation view taken along the lines IX-IX in FIG. 7;

FIG. 10 is a sectional elevation view taken along the lines X-X in FIG. 7 with parts broken away;

FIG. 11 is an isometric view of a portion of the operating mechanism on the carriage illustrated in FIGS. 7 through 10;

FIG. 12 is a sectional view of the carriage take along the lines XII-XII in FIG. 7;

FIG. 13 is a sectional elevation view taken along the lines XIII-XIII in FIG. 7;

FIG. 14 is an elevation view of a portion of the device shown in FIG. 2 taken from the viewpoint XIVXIV;

FIGS. 15 through 18 are schematic diagrams in straight line form of electrical circuits suitable for operating the device illustrated in FIG. 1 through 14; and

FIG. 19 is a schematic diagram of a modification of the control circuits suitable for controlling the device disclosed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION Although the device could be utilized with other types of speed control systems, it will be described as applied to an elevator system. FIG. 1 illustrates a simplified elevator system embodying the invention wherein an elevator car 1 is mounted for movement relative to a structure 2 having ten landings only some of which are shown. The elevator car is supported by a rope 3 which is reeved over a traction sheave 5 on the shaft of a suitable drive motor DM. The pattern generator and selector 9 is driven in synchronism with the movement of the car through a selsyn drive which includes a selsyn transmitter 11 connected to the shaft of the drive motor DM and a selsyn receiver 13 which is mechanically connected to the pattern generator and selector 9. The operation of such a selsyn drive is well known, therefore it is sufficient to say that the output shaft of the receiver 13 follows the position of the input shaft of the transmitter 11. The pattern generator and selector 9 can be drive in synchronism with the car by any suitable means such as a direct connection between the drive shaft of the motor DM and the pattern generator and selector 9, however, the selsyn drive permits flexibility of positioning the-pattern generator and selector and has other advantages which will become evident later. The important point is that the pattern generator and selector 9 have an input which is driven in synchronism with the movement of the elevator car.

The pattern generator and selector 9 which is the subject of this invention is controlled by and supplies information to a supervisory control system 15. Although almost any supervisory system could be easily adapted for use with the pattern generator and selector which is the subject of this invention, a suitable system is the one described in U.S. Pat. No. 3,519,106 issued in the name of Andrew F. Kirsch on July 7, I970.

The speed reference signal generated by the pattern generator and selector 9 serves as a pattern signal for a speed regulator 17 which controls the speed of the drive motor DM preferably in a closed loop system.

Referring to FIGS. 2 and 3 for a detailed description of the pattern generator and selector 9, a hollow shaft 21 is mounted for rotation about a vertical axis on a support structure 19 by a thrust bearing 23. A fixed shaft 25 concentrically mounted inside the hollow shaft 21 is rigidly held in place by a shoulder 25A and a nut 27 fastened to the threaded end of the shaft 25 extending below the support structure 19.

The fixed shaft 25 extends above the hollow shaft 21 where it is connected to a horizontal plate 29. The plate 29 is also connected to the support structure 19 by vertical supports 31 (only partially shown). The hollow shaft 21 supports and is rotated by a disc or turntable 33. The turntable is in effect a large gear. which is driven by pinion gear 34 in a manner which will be described later.

An advance gear 35 is concentrically mounted for rotation about the fixed shaft 25 above the hollow shaft 21. A control arm identified by the general reference character 37 is suspended by the general reference from the advance gear 35 by bracket 39, with the longitudinal axis of the control arm extending radially outward from the axis of the advance gear. Hence, it can be seen that as the advance gear is rotated the control arm 37 is swing through an are which is concentric with the axis of the turntable 33.

The advance gear 35 and therefore the control arm 37 can be rotationally driven by an advance motor AM connected to the fixed shaft 25 by bracket 43.

Preferably, the advance motor is a permanent magnet synchronous motor such as the Slow-Syn motor manufactured by The Superior Electric Company. The advance motor rotates the control arm through a clutch 45 such as a permanent magnet hysteresis clutch and pinion gear 47 which meshes with the advance gear 35.

Mounted on the control arm 37 is a carriage identified by the general reference character 49. The carriage 49 can be driven in either direction along the longitudinal axis of the control arm 37 by a threaded shaft 51. The threaded shaft 5] is rotationally driven by bevel gear 53 which is driven by another bevel gear 55 connected to a vertical shaft 57. The shaft 57 is rotated by the upper drive gear 6] on the hollow shaft 21 through pinion gear 59. It can be appreciated therefore, that as the turntable is rotated the carriage 49 is driven longitudinally along the control arm 37. The gearing of the drive coupling is such that the carriage tracks the spiral groove 63 embedded in the upper face of the turntable 33.

This spiral groove 63, which radiates outward from the center of the disc or turntable 33, in effect represents the hoistway in which the elevator ear operates, while the carriage 49 represents the elevator car. Therefore, while the turntable is driven in synchronism with the movement of the car and the carriage tracks the groove in the disc, the mechanism follows the position of the car in the hoistway. Floor stops which project above the surface of the disc 33 are inserted in the spiral groove 63 at points corresponding to the position of the various landings in the hoistway and are identified by the letters FS followed by the number of the landing. For example, the floor stop which represents the first floor is identified by the reference character FSI. Floor stops FSl through F S10 are shown in FIG. 2 for the ten floors of the structure shown in FIG. 1. Since the floors of the structure of FIG. 1 are assumed to be equally spaced, the floor stops are equally spaced angularly about the spiral groove. For installations where the floors are not equally spaced, the angular displacement between the floor stops would have to be adjusted accordingly. Although an installation with ten floors has been illustrated, it is to be understood that any number of floors may be accommodated. For very high rise buildings it might be necessary to employ a larger disc. The exact angular displacement between the floor stops is a function of the distance between landings and as will be seen shortly, the maximum speed desired for the particular installation.

As was mentioned previously, the device also incorporates a floor selector which, as is well known in the elevator art is a device which generates signals which keep the supervisory control system informed on the position" of the car. The supervisory system is concerned with the' gross position of the car, that is whether the car is to be considered at the first, second or third floor, etc. rather than with the exact position of the car intermediate the landings. In some types of floor selectors, a signal is generated that the car is at the next floor as soon as it leaves a given floor; however, in the selector illustrated, the floor indication is changed when the car passes the point halfway between landings. To this end, notching stops are angularly placed halfway between the floor stops. The notching stops are identified by the reference character N bracketed by the numbers of the floors between which the stop in located. For instance, the notching stop between the first and second floor is identified by the reference character 1N2 and is angularly located halfway between the floor stop PSI and F82.

In order to avoid interference between the device on the carriage which cooperates with the floor stops and the device on the carriage which cooperates with the notching stops, both of which will be described in detail later, the devices are placed at opposite ends of the carriage and track different portions of the spiral groove in the turntable. Thus, the floor stops are located in the outer half of the spiral where they are tracked by the outer end of the carriage while the notching stops are located on the inner half of the spiral where they are tracked by the inner end of the carriage. This arrangement is preferable because it places the floor stops, which it will be seen are instrumental in bringing the car into exact registry with the landings, in the outer grooves of the spiral where the scaling is'maximum.

The control arm 37 is instrumental in controlling the speed of the elevator car. Referring to FIGS. 3 through 6, it can be seen that a cam plate 65 is connected to the advance gear 35 for rotation therewith. The edge 65a forms a cam surface which is eccentric with respect to the center of rotation of the cam 65. A cam follower 67 includes an arm 69 pivoted about a screw 71 fastened to the plate 29 which is biased by a spring 73 so that a roller 75 pivotally connected to the arm 69 bears against the cam surface 65a. A segment gear 77 on the end of the arm 69 meshes with a pinion gear 79 connected to the shaft of a pattern potentiometer PP. This potentiometer may be similar to the pattern potenliam R. Caputo and William M. Ostrander. The roller 75 extends through a hole 81 in the plate 29 to bear against the cam surface 65a.

It can be seen that when the control arm 37 is in the position illustrated in FIG. 2, the cam follower 67 is centered with respect to the pinion gear 79 on the potentiometer. This is the neutral position of the control arm which is also shown enlarged in FIG. 4. In this position, the center tapped pattern potentiometer PP of the Caputo and Ostrander speed control system mentioned above is zero. As the control arm 37, which is rigidly connected to the advance gear 35, is rotated counterclockwise to the position shown in FIG. 5, the cam follower is rotated clockwise as shown to drive the pattern potentiometer to one of its limits. The pattern potentiometer'of the Caputo and Ostrander system generates a zero pattern signal when centered and progressively larger signals of onepolarity or the other as the SLIDER is displaced from the center position. The polarity of the signal thus generated determines the direction in which the car is to travel, while the magnitude of the signal determines the velocity at which the car is to travel.

Returning to FIG. 2, it can be seen that the turntable is rotated in the counterclockwise direction as the car travels upward so that the floor stops pass under the control arm in ascending order. It can also be seen from the arrows on FIG. 2 that when the advance motor is energized to initiate upward travel of the car, the pinion gear 47 rotates the advance gear and therefore the control arm 37 in the clockwise direction. As the cam plate is rotated with the advance gear, the segment gear on the cam follower will rotate the shaft on the potentiometer to generate a speed reference signal which will cause the car to begin traveling in the upward direction. It should be noted that the control arm is rotated in a direction opposite to the direction of rotation of the turntable so that the carriage 49 on the control arm advances more rapidly with respect to the floor stops on the turntable than the car actually advances with respect to the floors in the hatchway. This relative position generated by the rotation of the control arm is known in the elevator art as the advance car position. The difference between this position and the actual position of the car is proportional to the speed I commanded by the pattern potentiometer since the control arm and the pattern potentiometer were displaced in synchronism. Therefore, the advance car position represents the point at which the car could be brought to a stop at any given instant using a deceleration pattern similar to the acceleration pattern. In fact, it will be seen later that as the car approaches a floor at which it is to stop, the control arm will be coupled to the associated floor stop when the car is a distance equal to the advance distance away from the floor. Then as the car approaches the floor, the control arm will be driven towards the neutral position by the floor stop on the turntable thereby rotating the cam plate which in turn will progressively reduce the speed of the car until zero speed is reached when the car is level with the fioor.

In order to remove energization from the accelerating motor when the car has reached maximum speed, switches are located so as to be energized after the control arm reaches a point where the potentiometer is generating the desired speed. To this end, an up full advance switch UF A and a down full advance switch DFA are mounted on support rods 83 which in turn are connected to the plate 29 and vertical supports 85 mounted on the support structure 19. The appropriate switch will be operated by the control arm to discontinue acceleration after the control arm has reached the full advance position in the appropriate direction.

Elevator codes require that devices which operate independent of the normal speed control mechanism be provided as a backup for stopping the car as it reaches the upper or lower terminal, should the normal speed control system fail. conventionally, switches are provided in the hatchway to positively check for the position of the car. The speed of the car is checked as the car passes these points in the hatchway to assure that the normal speed control system is slowing the car down properly. A final slow-down switch is also pro vided which shuts the motor down and applies the brake immediately if the car should travel a predetermined distance beyond either terminal landing. As part of a terminal slow-down system, up and down terminal slow-down switches TSUl and TSDl are mounted on the support bars 83. These switches can be employed in circuits not shown which would initiate emergency stopping of the car, should the car approach a point at which nonnal slow down for a terminal landing should be initiated and the control arm is still in the full advance position.

Additional terminal slow-down switches provide an additional check on the speed of the car as it approaches a terminal. As can be seen in FIGS. 4, and 6, the cam plate 65 is provided with an arcuate cam surface 65b which projects upward from the upper surface of the cam plate 65. The additional terminal slow-down switches TSU2 and TSD2 mounted on the plate 29 are provided with roller equipped operating levers 87 which cooperate with the cam surface 65b. It can be seen from FIG. 4 that when the control arm 37 is in the neutral position wherein a zero pattern speed is generated, that neither of the switches TSU2 or TSD2 are operated by the cam surface 6512. On the other hand, when the car is traveling at full speed in the down direction, it can be seen from FIG. 5 that the switch TSD2 is operated by the cam surface 65b. It can be appreciated that as the control arm 37 travels towards the neutral position during slow-down that at a given position of the control arm corresponding to a given speed, the switch TSD2 will be dropped out. If this switch has not dropped out by the time that the car reaches a predetermined point in the hatchway short of the lower terminal as determined by independent switches not shown, the terminal slow-down system takes over. The switch TSU2 cooperates similarly with the cam surface 651) as the car approaches the upper terminal.

The cam surface 65!) operates two additional switches RSDM and RSUM which are similar to the switches TSU2 and TSDZ. These two switches, the reset down master switch and the reset up master switch. respectively, are utilized to center the control arm. it is important that the control arm 37 be in the neutral position as shown in FIG. lbefore an attempt is made to start the car, since if the control arm is displaced from the neutral position the resultant pattern speed called for by the position of the control arm can cause unacceptable rates of change of acceleration. For instance, should a passenger operate the emergency stop button to stop the car between the floors, the control arm 37 would not come to rest in the neutral position. It is desirable under these conditions to return the arm to the neutral position before the car is restarted.

With the control arm 37 in a neutral position as shown in FIG. 4, the rollers on the operating levers of the switches RSDM and RSUM are just off the opposite ends of the cam surface 65b so that neither switch is operated. With the control arm in the full advance position as shown in FIG. 5, the switch RSUM is operated by the cam surface 65b while the switch RSDM is dropped-out. The location of these two switches is such that if the control arm is displaced either side of the neutral position an amount corresponding to a displacement of the elevator car more than one-quarter of an inch above or below the level of the landing, one of these switches will be operated. it can be appreciated from FIG. 4 that with the control arm displaced from the neutral position in a counterclockwise direction wherein it generates a down direction speed reference signal as shown by the arrow, that the reset up master switch RSUM is the one that is actuated by the cam surface 65b. If the arm is to be reset under these conditions, it will be seen in circuits described below that the switch RSUM will cause the advance motor to move the control arm in the clockwise direction, which is the up advance direction as shown by the arrow. However, when the control arm reaches the neutral position and the switch RSUM drops-out, the control arm will come to rest. An alternative arrangement for centering the control arm will be discussed below.

Another accurate cam surface 65c having a shorter radius than cam surface 65b, operates a switch Z when the control arm is in a position corresponding to the car being within 15 inches of a landing during slowdown. Actuation of this switch is utilized to preopen the doors and for another operation to be described below.

Details of the construction of the control arm 37 and the carriage 49 mounted thereon are illustrated in FIGS. '7 through 13. The carriage 49 includes a backplate 911, front-plate 93 and a center plate 95. The front and back plates are connected near their upper extremities by tie rods 97 on either side. The tie rods 97 assist in supporting and guiding the carriage through cooperation with a guide block 99 on the main frame 89 of the control arm. The center plate is rigidly connected to the back-plate through upper and lower spacer bars 101 on either side of the plates. The center plate 95 and the front plate 93 are connected by center strap 103 through a support block 105 and a drive block 107 connected to the center plate and the front plate respectively.

Left-hand and right-hand pawl pieces 109L and 109R are pivotally connected to the support block 105 for arcuate movement in the vertical and horizontal directions. An appreciation of the construction of the pawl pieces can best be gained by reference to the isometric view of FIG. ill. The horizontally extending legs 109a of the pawl pieces are pivotally connected to pivot block 111 by pins ll 13 for arcuate movement in a vertical plane. The pivot blocks lllll are pivotally connected to the support block 105 by pins 115 which permits arcuate movement of the pawl pieces in a horizontal plane. Top links 117 are rigidly connected to the pivot blocks 1 1 1 through spacer blocks 1 19 for arcuate movement in a horizontal plane about the pins 1 15 with the pawl pieces.

Horizontally depending flanges 1 17a on the top links receive adjusting screws 121 which bear against a stop 123 mounted on the center strap 103. A spring 125 connected between the free ends of the top links 117 biases the adjusting screws against the stop. This tends to hold the pawls in fixed horizontal relation with respect to each other. It will be seen later that this arrangement is useful in absorbing the chocks encountered when a pawl captures a floor stop. Compression springs 127 which are held in place between the top links 117 and the pawls 109 by screws 129 bias the pawls vertically downward to the extended position illustrated in FIG. 7.

The pawl pieces 109L and 109R are provided with pawl lifters 131L and 131R, respectively, each having horizontal extensions 131a which overlap. As can be seen from FIG. 10, with the pawl pieces biased to their extended position by the spring 127 the pawls 109p are in a position to engage the floor stops F8 on the turntable 33. Under these conditions, the lifter rod 133 connected to the actuator rod 135 is in a substantially horizontal position. However, if the actuator rod is rotated in a counterclockwise direction, the lifter rod 133 is rotated to a substantially vertical position thereby raising the arms 131a of the pawl lifters to the position partially shown by the dashed lines in FIG. 10. This results in lifting the pawls 109p to a position (not shownlwherein they clear the floor stops FS.

Referring to FIGS. 7 and 12, it can be seen that the actuator rod 135 is rotated by a rotary solenoid 137 mounted on the back-plate 139 of the control arm through segment gear 141 and pinion gear 143. The pawls are also individually lifted by the inclined arms 13117 on the pawl lifters when they come in contact with the bars 83 (see FIG. 2) as the control arm approaches the respective full advance positions.

A striker plate 145 is slotted at the top and pinned to the front plate 93 by pin 147 for vertical movement (see FIGS. 9 and The striker plate is guided in its vertical movement at its lower end by a grooved stub 149 which rides in a vertical slot 151 in the front plate 93 as can be best seen from FIGS. 7 and 9. Spacers 153 on the striker plate 145 also bear against the front plate 93. The cut-outs in the striker plate are provided for the threaded shaft 51 and the lifter and actuator rods 133 and 135. The striker plate 145 is provided with a horizontal lip 155 which raises the striker plate 145 whenever a floor stop FS passes under the control arm. The striker plate 145 is biased in the downward direction by a leaf spring 157 connected to the plunger switch PL mounted on the vertical extension of the front plate 93. When a floor stop lifts the striker plate, the leaf spring is deflected until it actuates the plunger switch PL.

The three-wire signal generator for the floor selector can best be seen by reference to FIGS. 7, 8 and 13. A six pointed star-wheel 161 is mounted on a hollow shaft 163 which is concentric with the threaded shaft 51 between the back plate 91 and the center plate 95 of the carriage. Three elliptically shaped cams CA, CB

and CC are also mounted on the shaft 163 for rotation with the star-wheel 161. The axis of the cams are offset 60with respect to each other so that the lobes of the cams are each aligned with a pair of points on the starwheel. For instance, as can be seen in FIG. 13 the lobes of the cam CC are aligned with the points 161C of the star-wheel. A second star-wheel 165 cooperates with a spring biased indexer 167 to assure that the star-wheel may only come to rest with the points oriented as shown in FIG. 13. The points of the star-wheel 161 extend below the bottom of the carriage a sufficient length so that they are engaged by the notching stops on the turntable as they pass under the control arm. The indexer 167 and the second star-wheel 165 assure that the star-wheel 161 advances exactly 60 each time a notching stop ispassed. The cams CA, CB and CC are effective to operate plunger switches SA, SB and SC, respectively through leaf spring actuating levers 169 when the major axis of the associated cam is oriented vertically. It can be appreciated that only one of the switches SA, SB or SC is operated at any one time. However, the sequence in which they are operated is dependent upon the direction of rotation of the starwheel 161.

As was mentioned previously, the shaft 51 is rotated in synchronism with the rotation of the turntable 33 in order that the carriage may track the spiral groove in the turntable. This is accomplished through the threaded drive block 107 which it will be remembered is connected to the front plate 93 of the carriage. Reference to FIG. '7 will show that a roller 171 mounted on the vertical extension of the control arm frame 89 bears against the upper surface of the turntable near the outer edge to give support to the control arm.

The turntable may be driven in synchronism with the movement of the car in any suitable manner such as by a tape drive or a direct gear drive and may be either located in the penthouse near the drive machine or on the car. In the preferred embodiment of the invention, the device is located in the penthouse near the supervisory control apparatus and is driven by a selsyn drive. Referring to FIGS. 2 and 3, it can be seen that the selsyn receiver 13 operates through a clutch 173 to rotate a pinion gear 175 on a shaft 177. Pinion gear 175 engages idler gear 179 on the stub shaft 181 to rotate the pinion gear 34 which meshes with the teeth machined into the edge of the turntable 33.

A small direct current correction motor CM mounted on a support 183 is operative through gear reducer 185 to rotate pinion gear 187. Pinion gear 187 meshes with gear 189 on the clutch mechanism 173 which is also effective to rotate the shaft 177 and therefore rotate the turntable 33 through the gear 34.

The clutch mechanism 173 includes a pair of clutch plates 191 the upper one of which is connected to and rotates with a drum 193. A pair of actuator arms I95 pivotally mounted to the block 197 support rollers 199 which lift the drum 193 and therefore separate the clutch plates 191 when the actuator arms are rotated in a counterclockwise direction. Counterclockwise rotation of the actuator arms 195 is imparted by a pair of clutch solenoids CS mounted on the support 183 which attract a steel plate 201 connecting the free ends of the actuator arms when the solenoids are energized. The

clutch plates 191 are biased to their engaged position by tension springs 203. r

With the clutch solenoids deenergized, the'tumtable is driven in synchronism with the movement of the car by the slesyn receiver 13. As will be seen later, it is possible under certain circumstances for the turntable to be slightly out of synchronization with the exact position of the carwhen the car comes to rest at a landing. Under these circumstances, the clutch solenoids CS are energized to disengage the selsyn receiver 13 and the position of the turntable is adjusted through the correction motor CM.

A horizontalarm 205 is radially supported above the turntable 33 out of the way of the control arm 37 by vertical support 207 at its outer periphery and by a bracket 209 connected to the plate 29 as can be seen in FIG. 14. Avertical member 211 and a brace 213 connected to-the bracket'209 support a bar 215 above the arm 205. Thevertical member 211, the bracket 209 and another bracket 217 support a threaded shaft 219 for rotation about an axis parallel to the arm'205. An auxiliary carriage "221 straddling the bar- 205 is threadedly advanced along the bar 205 by the threaded shaft 219. The auxiliary carriage 221 is driven in synchronism with the movement of the car by pinion gear 223 which meshes with the lower drive gear 225 mounted on the hollow shaft 21 through stub shaft 227 and a pair of bevel gears 229. Mechanical stops 231 are rigidly connected to the bar 215 where they will engage the auxiliary carriage 221 at points-corresponding to the limits of travel in the inward and outward direction of the carriage 49 carried on the control arm 37. This arrangement is provided to prevent damage to the carriage 49 should the carriage 49 tend to go beyond its limits of travel during the resynchronization mentioned above. When the auxiliary carriage 221 comes in contact with the mechanical stops 231 the turntable will be restrained and the clutch 173 will slip to prevent damage to the speed control mechanism.

CONTROL CIRCUITS The control circuits for the mechanism are illustrated in FIGS. 15 through 18 with a modification shown in FIG. 19. The circuits are shown in conventional straight-line form with the contacts of the various relays identified by the same reference character as the coil with a suffix indicating the number of the contacts. For instance, the first set of contacts for the master up direction relay having a coil 81UM is identified by the reference character 81UM1. Normally open make contacts which are only closed when the associated coil is energized are illustrated by the symbol illustrated for the contacts RSDI while normally closed break contacts which are opened when the coil is energized are illustrated by the symbol shown for contacts RSD2.

The relays shown in FIG. 15 are energized when the associated circuit between direct current busses L+- and L- are completed. The master up direction relay 81UM is energized when the contacts 810! of the up direction relay (not shown) are closed. Similarly, the

direction circuits to indicate the direction in which the car should travel. The relay 81UM may also be energized through the make contacts B1 of the terminal resynchronizing relay B if the contacts RSDl of the reset down relay are closed. The relay 81UM will remain energized as long as the contacts B1 remain closed through the holding contacts 81UM1. Similarly, the down direction master relay 81DM may be energized through the contacts B1 and held in through the holding contacts 81DM1 if the contacts RSUl'of the reset up relay are closed.

Make contacts 81UM2 and 81DM2 complete a circuit for the energization of the go-up relay GU and the go-down relay GD, respectively, as longas the control arm is in the neutral position so that the break contacts RSU2 and RSD2 are closed. As a further check, the make contacts Zlof the Z-switch mustbe closed to indicate that the control arm is in a position representativeof the car being within at least 15 inches from a landing. The contacts GUI of the go-up relay complete a circuit for the energization of the up direction relay 1 as long as a slow-down signal is not being generated,

break contacts 34X1 are closed; the down direction relay is not energized, contacts 2-1 are closed; a car has not reached the top limit of travel, switch TL is contacts 1-1 are closed; the bottom limit switch BL is closed; and the safety contacts 29-1 are closed. Again the down direction switch remains energized through the holding contacts 2-2. Energization of the up running relay 1 or the down running relay 2 results in energization of the running relay 3. Once the car is running, the make contacts STl of the stop timer relay (not shown) are closed. These contacts remain closed until a predetermined time after the car has slowed down below a predetermined speed. For example, these contacts may remain closed until 5 seconds after the car has slowed-down below 30 feet per minute. Therefore, the up and down running relays 1 and 2 remain energized after a slow-down signal is generated through the contacts STl so that the car speed may be controlled by the speed control all the way down to a full stop.

The auxiliary slow-down relay 34X is energized by the make'contacts 34-1 of the conventional slow-down relay (not shown) as long as the terminal resynchronization relay is dropped-out to close the contacts B2 and as long as the contacts X1 of the notching relay are closed. The contacts 34-1 are closed by the conventional circuits of a supervisory system which generate a slow-down signal as the car approaches a floor at which a car call or a floor call for which the car is to stop is registered. Once energized the auxiliary stopping relay 34X remains energized as long as the contacts 34-1 are closed through the holding contacts 34x2.

The reset up relay RSU is energized if the car comes to rest (break contacts 3-1 of the running relay are closed) with the control arm in a position so that the cam surface 65b closes the contacts on the switch RSUM as described in connection with FIGS. 4 and 5. Similarly, the reset down relay RSD is energized if the car comes to a stop in a position where the cam surface 65b operates the switch RSDM.

The recentering relay C, which is effective to return the control arm to the neutral position, is energized if the car comes to rest with the arm displaced from the neutral position so that either the contacts RSU3 or RSD3 are closed; as long the resynchronizing relay is not energized, contacts A1 are closed; and as long as either the terminal resynchronizing relay is energized, contacts B3 are closed; or a floor stop is not captured by the pawls, contacts PLAI are closed; or if a pawl is captured, the car is not level with a landing, contacts LTl of the landing timer relay (not shown) are closed.

The landing timer relay may be part of a system such as that disclosed in U.S. Pat. No. 3,138,223 wherein a photoelectric unit and a plate with a slot therethrough are utilized to cutoff the power and set the brake when the car is in exact registry with a landing. It is to be understood that other types of devices which perform this function could be utilized. Once the relay C is energized it is held in by holding contact C1 until the arm is centered to open both the contacts RSU3 and RSD3.

If the car should come to rest at a landing, contacts LT2 are closed; with the control arm out of the neutral position so that either contacts RSU3 or RSD3 are closed; and if a floor stop is captured by the pawls, contacts PLA2 are closed, the resynchronization relay A will be energized if the control arm is in a position indicating that the car is within inches of the floor, contacts Z1 are closed. If under these conditions the control arm is in a position indicating that the car is more than 15 inches from the floor, contacts 21 will be open but the break contacts Z2 will be closed to energize the terminal resynchronizing relay B. Once energized the B relay is held in through holding contacts B4 until the car reaches one terminal or the other so that either the contacts T69 or B69 of the conventional terminal relays (not shown) are opened. If the car is already at a terminal floorwhen this occurs so that either contacts T69 or B69 are open, the relay B will be held in by make contacts RSU4 or RSD4 until the control arm is centered.

The rotary pawl solenoid PS is energized while the car is running through the contacts 3-2 of the running relay until a slowdown signal is generated and the break contacts 34X3 of the auxiliary slow-down relay open. The pawl solenoid is also energized to lift the pawls during resynchronization when the make contacts C3 of the centering relay are closed.

The direct current correction motor CM is energized with the proper polarity to rotate the turntable in a desired direction during resynchronization when the contacts A2 are closed by either the make contacts RSUS or RSD5. The back-to-back Zener diodes 201 and ZD2 shunting the correction motor CM apply the proper voltage to the motor CM for both directions of rotation. The clutch solenoids CS1 and CS2 are energized through the same circuit. These coils and the resistor R1 cooperate with the Zener diodes to assure the proper voltage drop across the motor CM.

The three-wire signal generator mounted on the carriage and described above applies a signal through either switch SA, SB or SC to energize the selector motor SEL. This motor is a conventional three-wire stepping motor which indexes in the appropriate direction depending upon the sequence of the three input signals. For instance, if the car is traveling in the up direction so that the switches are closed in the order of SA, SB and then SC the selector motor will advance in a direction to indicate an upward movement of the car, while if the signals are generated in the order of SA, SC, SB the motor SEL will rotate in the opposite direction to indicate a downward movement of the car. A suitable motor of this type is described .in U.S. Pat. No. 1,913,043 mentioned above.

Closure of the contacts SA, SB or SC results in energizing the pulse shaper PA, PB or PC to apply a pulse to the input M of the latching type mercury wetted switch X. The relay X has a second input N by which the contacts may be reset. This type of relay wherein the contacts remain in a given position until a pulse is applied to the other input is well known in the art. The relay X is reset by closure of the pawling switch PL mounted on the carriage and described above. Closure of the contacts PL also energizes the auxiliary pawling relay PLA.

FIG. 17 illustrates the circuits for the advance motor AM. This motor is a permanent magnet type synchronous motor having three terminals. By placing a phase shifting network composed of the capacitor C1 and resistor R2 across the terminals 2 and 3, the direction of rotation of the motor can be determined by applying a voltage across terminals 1 and 2 or terminals 1 and 3. The motor is energized by 1 15 volts 60 cycle AC applied across the busses B1 and B2. The motor AM will be energized to drive the control arm in the up advance direction when the up running relay is energized to close contacts 1-3. Energization to the motor will be terminated when the control arm reaches the full advance position and the up full advance switch UFA opens. Should the car not reach full speed before a slow-down signal is generated, the contacts 34X4 will open to terminate energization of the motor AM. Similarly, a voltage is applied across the terminals 1 and 3 to drive the advance motor in the opposite direction when the contacts 2-3 of the down running relay close until the control arm reaches the full advance position in the down direction and the switch DFA opens or slow-down is initiated to open the contacts 34X4. The motor AM will also be energized to drive the control arm in the proper direction during recentering when the contacts C4 are closed through either the contacts RSU6 or RSD6.

FIG. 18 illustrates the circuits for generating the floor position signals for the supervisory control. The selector motor SEL drives a wiper arm WA to successively complete a circuit between the busses L+ and L- for energizing the appropriate floor position relays 1F through 10F. The sequence in which the switches SA, SB and SC in FIG. 16 are generated determine the direction in which the wiper arm advances.

FIG. 19 illustrates an alternative method of generating a signal to indicate that the control arm is not in the neutral position. In place of the mechanical switches RSUM and RSDM which are operated by the cam surface a on the cam plate, mercury wetted polarized relays RSUM and RSDM may be utilized to electrically detect the displacement of the control arm through the accompanying voltage produced by the pattern potentiometer PP. With the pattern potentiometer PP energized by a fullwave rectifier in a manner similar to that disclosed in the Caputo and Ostrander application mentioned above, displacement of the movable tap 77 to either side of the fixed tap will generate a signal on the lead 233. The difference between this signal and ground is amplified by the operational amplifier 235 and applied across the relays RUSM and RSDM. Backto-back Zener diodes ZD3 and ZD4 provide that this amplified voltage must be above a predetermined threshold before it is applied to relays RSUM and RSDM. In the example given, the Zener diodes have a threshold of 4 volts and the parameters of the circuit are such that, when the variable tap 77 is in a position corresponding to a car position of less than one-quarter inch above or below a landing, insufficient voltage will be passed to the relays RSUM and RSDM to energize them. The polarities of the. relays are such that when the variable tap is offset more than an amount corresponding to a car displacement of a quarter of an inch to produce a positive voltage at the output of the amplifier 235 the relay RSUM will be energized. Similarly, a sufficiently large negative voltage will operate the relay RSDM. These relays are very sensitive and will give a positive response to a voltage on the order of 0.63 volts of the appropriate polarity. Such an arrangement provides a more precise indication of the position of the control arm than the use of the mechanical switches and cam described above.

OPERATIONS It would be useful at this time to describe a few typical operations of the system. Assume that the car is at rest at the first floor with the control arm 37 centered. Under these conditions the wiper arm WA of the floor selector would be positioned as shown in FIG. 18 to energize the relay 1F thereby indicating to the supervisory system that the car is at the first floor. With the car at rest, the relays 81UM, 81DM, GU, GD, 1, 2 and 3 are all deenergized. With the control arm centered the contacts RSUM and RSDM are both open.

Assume that a passenger enters the car and registers a call for the fourth floor. Through conventional supervisory control circuits (not shown) the contacts 81U1 in FIG. 15 of the up direction relay will be closed to energize the relay 8lUM. Since the control arm is in the neutral position the contacts RSU2, RSD2 and Z1 willbe closed so that the contacts 81UM2 of the up direction master relay will complete a circuit for the energization of the go up relay GU. With the auxiliary slow-down relay dropped-out, contacts 34X1 closed, and upon the closure of the doors to energize the safety relay so that contacts 29-1 are closed, the contacts GUI of the go up relay will complete a circuit for the energization of the up running relay 1 and the running relay 3. Closure of make contacts of the relay 1 (not shown) will complete circuits for the energization of the drive motor in a manner well known in the elevator art.

Closure of the make contacts 3-2 of the running relay will complete a circuit for the energization of the rotary pawl solenoid PS. Energization of this solenoid will cause rotation of the shaft 135 (see FIGS. 7, 10 and 12) to cause the lifter rod 133 to raise the pawls 109 clear of the floor stop FSl, through the pawl lifters 131.

Closure of the make contacts l-3 in FIG. 17 completes a circuit for energization of the advance motor AM with the proper phase relationship so that it is effective to rotate the advance gear 35 through hysteresis clutch 45 in a clockwise direction to cause the control arm to begin rotating in a clockwise direction. 'Rotation of the advance gear 35 causes clockwise rotation of the cam plate 65. The eccentric cam surface 65a causes the cam follower 67 to rotate the shaft 79 on the pattern potentiometer PP thereby generating a speed reference signal which initiates upward movement of the elevator car.

Movement of the elevator car causes the selsyn transmitter 11 to induce rotation of the selsyn receiver 13 which in turn drives the turntable in the counterclockwise direction in synchronism with the movement I system that the car is in the vicinity of the second floor.

Closure of the second switch SB causes the pulse generator PB to pulse the relay X to close the contacts X1 which has no effect on the system at this time.

As the advance motor continues to drive the control arm in the clockwise direction, the continued rotation of the cam plate causes the pattern potentiometer PP to command a continually increasing speed. This rotation of the cam plate 65 causes the cam surface 65b to actuate the switch RSDM which has no effect on the system at this time since the contacts 3-1 of the running relay are open. Closure of the switch TSU2 also has no effect on the system at this time.

As the control arm continues to advance, it reaches a position where the frame 89 activates the switches TSUl which has no effect on the system at this time and the up full advance switch UFA. Opening of the switch UFA terminates energization of the advance motor AM therefore bringing the cam plate and the variable tap on the pattern potentiometer PP to rest. The car therefore levels off at maximum speed in the up direction.

Passage of the floor stop FS2 under the control arm lifts the striker plate on the end of the carriage (see FIGS. 9 and 10) to momentarily actuate the pawl switch PL. Closure of the contacts PL applies a signal to the latching switch X which opens the contacts XI. The contacts X1 remain open after the floor stop has passed and the contacts PL reopen. Closure of the contacts PL also momentarily energizes the relay PLA which has no effect on the system at this time. The floor stop F52 passes freely under the carriage since it will be recalled that the pawl solenoid PS is energized at this time to hold the pawls in the retracted position.

As the car continues upward, the notching stop 2N3 will index the floor selector to register the third floor as the advance position of the car although the car will be somewhat more than a full floor behind this position. It can be appreciated from FIG. 2 that at any time during movement of the car the position of the control arm represents the advance car position, or the position at which the car could be brought to a stop, while the neutral position of the control arm represents the actual car position. Since there is no call registered for the third floor, the car continues to move in the upward direction at full speed.

Closure of the switch SA by the rotation of the starwheel by the notching stop 3N4 causes the floor selector to index to energize the relay 4F and causes the pulse shaper PA to energize the latching relay X to close the contacts X1.

Conventional supervisory circuits will then be operative to energize the slow-down relay (not shown) to close the contacts 34-1 in response to the car call registered for the fourth floor. With the contacts B2 and now X1 closed, the auxiliary slow-down relay 34X will be energized and held in through its make contacts 34x2. Despite the opening of the contacts 34Xl the run up relay 1 and running relay 3 will remain energized through the contacts STl of the stop timer relay. However, opening of the contacts 34x3 will result in deenergization of the pawl solenoid PS. With this solenoid deenergized the springs 127 between the top links 117 and the pawl pieces 109 urge the pawls to extend below the carriage.

The arm l3lb of the pawl lifter 131L is restrained by the bar 83 so that the pawl 109L will remain lifted. However, as the turntable continues to rotate in synchronism with the movement of the car, the floor stop PS4 for the fourth floor will engage pawl 109P of the pawl piece 109R. Capturing of the floor stop will cause the striker plate 145 to close the pawling switch PL thereby resetting the relay X. Opening of the contacts Xl has no effect on the system at this time, since the holding contacts 34x2 provide energization for the auxiliary stopping relay 34X. It can be appreciated at this point that the purpose of the relay X is to provide a window in which a decision can be made as to whether the car can be stopped at the floor indicated by the advance car position. This so-called window is open from the time that the floor selector is advanced to the new floor position by the notching stop and the time that the floor stop for the associated floor passes under the carriage as indicated by the pawling switch PL. Once the floor stop has passed under the carriage it is impossible for the car to stop at that floor even though the floor selector still indicates the car to be in the vicinity of the fourth floor.

With the control arm coupled to the turntable, it is rotated in the counterclockwise direction as the car continues its upward movement. This results in a continuous reduction in the speed of the car as the cam follower which adjusts the setting of the pattern potentiometer PP follows the cam surface 65a on the cam plate 65. The fact that the switch RSUM remains operated by the cam surface 65b has no effect on the system at this time, since the contacts 3-] of the running relay remain open. Continued rotation of the turntable effects a smooth slow-down of the car as the control arm approaches the neutral position. As the control arm approaches a point corresponding to the car being inches from the fourth floor, the cam surface 65c operates the switch Z. Closure of this switch is operative through conventional circuits (not shown) which initiate opening of the doors as the car approaches the floor. When the control arm reaches the neutral position, the pattern speed reaches zero with the running relay and the run up relays energized. As mentioned above, 5 seconds after the speed of the car goes below 30 feet per minute, the relay ST drops-out to open the contacts STl thereby deenergizing the up running relay 1 and running relay 3. With the control arm in the neutral position, the switches RSUM and RSDM will not be operated by the cam surface 65b on the cam plate 65, and the system described will come to rest until another call is initiated.

Assume now however, that as the car was traveling upward at full speed that a passenger operated the emergency stop button. As is customary under such conditions, the power is removed and the brake is applied independent of the normal slow-down system. Under these conditions, the car would come to a stop somewhere between the floors with the control arm remaining in the full clockwise position. If the car were restarted at this point under the control of the normal speed control system, unacceptable rates of acceleration would be encountered.

However, with the control arm in the full clockwise position, the switch RSDM is operated by the cam surface 65b. Since the running relay 3 is deenergized at this time, the reset down relay RSD will be energized through the contacts 3-1. With the contacts RSD2 open, neither the go up or go down relays can be energized to restart the car. Assuming for the moment that the car comes to a stop at a spot other than within one quarter inch of a landing, the relay C will be energized through contacts RSD3 of the reset down relay, the contacts LT1 of the landing timer relay and the break contacts Al. Relay A cannot be energized because the contacts LT2 in addition to the contacts Zl will be open.

Pick-up of the relay C results in closing of the holding contacts Cl and pick-up of the pawl solenoid PS through the contacts C3. Closure of the contacts C4 results in energization of the advance motor AM through the make contacts RSD6 and the closed down full advance switch DFA to cause the control arm to rotate in the counterclockwise direction as it would during acceleration in the down direction. With the pawl solenoid energized, the control arm can be returned to the neutral position without engaging any of the floor stops on the now stationary turntable.

As the control arm returns to the neutral position the notching stops can operate the star-wheel to index the floor selector so that it will indicate the proper position of the car, when the control arm returns to the neutral position. When the control arm reaches the neutral position the switch RSDM will open to drop the relay RSD resulting in the deenergization of the advance motor and the drop-out of the pawl solenoid through the deenergization of the C relay. With the contacts RSUZ, RSD2 and Z1 now all closed, the registered calls can reinitiate movement of the car. Since the control arm is in the neutral position, normal acceleration and control will be affected.

Assume now that the control of the speed of the car is transferred to a landing inductor system such as that described in US. Pat. No. 3,207,265 for final landing as the car approaches within a couple of feet of the floor. Assume further that the car is brought to a stop 

1. A speed reference generator adaptable for use in an elevator system including a structure having a plurality of floors, an elevator car mounted for movement relative to the structure to serve the floors and a speed regulator for regulating the speed of the elevator car in response to a speed reference signal generated by the speed reference generator, said speed reference generator comprising, a disc having a spiral pattern radiating from the center of one face of said disc, floor stops mounted on the spiral pattern at points corresponding to the location of the landings, a shaft passing through the center of the disc perpendicular to the plane of the disc, drive means for rotating the disc about the axis of said shaft in synchronism with the movement of the car, a control arm pivoted about said shaft with the longitudinal axis of said control arm substantially parallel to the plane of the patterned face of said disc, a carriage mounted for longitudinal movement along the control arm, coordinating means for causing the carriage to move longitudinally along the control arm in synchronism with the rotation of said disc so that the carriage tracks the spiral pattern on the disc, reference signal generating means connected to said control arm for generating a speed reference signal as a function of the rotational displacement of the control arm about the shaft from a neutral position, accelerating means operative to rotationally displace said control arm from the neutral position in a direction opposite to the direction of rotation of the disc for a given direction of car movement thereby causing the reference signal generating means to generate a speed reference signal while advancing the carriage along the spiral pattern a distance proportional to the speed reference signal, coupling means mounted on the carriage and operative from an uncoupled condition to a coupled condition wherein it couples the carriage to a floor stop on the disc, thereby causing the control arm to be rotated with the disc, and means generating a control signal for operating said coupling means to the coupled condition when it is desired that the car be brought to a stop whereby the control arm will be driven towards the neutral position by the next floor stop to approach the coupling means thereby causing a reduction in the speed reference signal.
 2. The speed reference generator of claim 1 including limit means for rendering the accelerating means ineffective to further displace the control arm from the neutral position beyond a predetermined position, said predetermined position providing sufficient rotational displacement of the control arm from the neutral position that the reference signal generating means generates a desired maximum speed reference signal.
 3. The combination of claim 1 wherein said coupling means comprises pawling means operative from a retracted condition to an extended condition wherein it is engaged by a floor stop.
 4. The combination of claim 3 including an operating device for operating said pawl means between said retracted and extended conditions, said operating device being connected to said control arm adjacent the pivot point of the control arm, said combination including linkage means for connecting the operating device to the pawling means mounted on the carriage whereby the mass of the control arm is concentrated adjacent its pivot.
 5. The combination of claim 1 including resetting means operative to return the control arm to the Neutral position when the car stops with the control arm displaced a substantial distance from the neutral position.
 6. The combination of claim 5 including means responsive to said resetting means for preventing the restarting of the car under control of the speed regulator until said control arm is reset to said neutral position.
 7. The combination of claim 5 wherein said accelerating means includes an electric motor and wherein said resetting means comprises said electric motor and direction circuits responsive to the direction of displacement of the control arm from the neutral position and operative to energize said electric motor with the proper polarity of current to drive said control arm towards the neutral position.
 8. The combination of claim 5 including detector means for independently determining that the elevator car is adjacent a landing, and means responsive to the indication from the detector means that the car is adjacent a landing and to the resetting means that the car has stopped with the control arm displaced a substantial distance from the neutral position for rotating the coupled disc and control arm until said control arm reaches the neutral position.
 9. The combination of claim 8 including terminal stopping means and means responsive to the displacement of the control arm more than a predetermined amount from the neutral position when the car is stopped and responsive to the indication of the detector means that the car is adjacent the landing for running the car toward a terminal landing where it is stopped by the terminal stopping means.
 10. The combination of claim 1 including notching signal generating means operative to generate a notching signal when triggered and notching stops connected to the spiral pattern at points where they will trigger the notching signal generator means as the car moves from one landing to the next.
 11. The combination of claim 10 wherein said spiral pattern is divided into two sections, with one section extending from the center of the disc outward to a predetermined point and with the other section extending from the predetermined point outward, wherein said floor stops are connected to a first section of said spiral pattern at points corresponding to the position of the landings, wherein the notching stops are connected to the second section of the spiral pattern at points corresponding to the notching points between landings, and wherein the pawling means are mounted on the carriage for tracking the first section of the spiral pattern and the notching signal generating means are mounted on the carriage for tracking the second section of the spiral pattern.
 12. The combination of claim 11 wherein said first section of the spiral groove is said other section and wherein said second section is said one section whereby said floor stops and pawling mean cooperate with the outer section of the spiral groove where the scaling approaches the maximum.
 13. The combination of claim 11 wherein the notching signal generating means includes encoder means for generating one of three separate signals each time the signal generating means is triggered by a notching stop, said signals being generated sequentially in a first order while said car is traveling in a first direction and being generated sequentially in reverse order when the car is traveling in the opposite direction.
 14. The combination of claim 13 wherein the notching signal generating means includes an operating shaft connected to said encoder and an indexer mounted for rotating said operating shaft, said indexer being incrementally advanced causing incremental rotation of the operating shaft each time a notching stop on the disc passes the indexer, said encoder being operative to generate one of said three separate signals in response to the rotational position of the operating shaft. 